Air compressor



Aug. 5, 1958 J. w. BLOUNT ET AL 2,846,139

AIR COMPRESSOR Filed March 13, 1956 2 Sheets-Sheet 1 Gro ver 6. Mc Gul/ar Joseph W. B/aunf Y INVENToRs.

5mi ik BY United States Patent AIR CONIPRESSOR Joseph W. Blount, Prichard, and Grover G. McCullar,

Mobile, Ala. l

Application March 13, 1956, Serial No. 571,339

2 Claims. (Cl. 230-170) This invention relates in general to new and useful improvements in pump construction, and more specically to a pump primarily intended to be used as an air compressor.

The primary object of this invention is to provide an air compressor which may be used by dentists, doctors and others where an air spray is required, the air compressor being so constructed whereby the internal working parts thereof are free from oils and other foreign matters normally found in air compressors.

Another object of this invention is to provide an improved air compressor of the diaphragm type, the air compressor including a housing having a cylinder insert, the diaphragm being provided with a piston type diaphragm support, the cylinder insert being formed of a self-lubricating material and the diaphragm support being mounted therein for reciprocatory movement.

Still another object of this invention is to provide an improved pump of the type which includes a housing having a cylinder insert, the cylinder insert being formed of an oil impregnated porous material and there being provided a suitable supply of oil for the oil impregnated material.

Another object of this invention is to provide an improved pump which includes a housing having mounted therein a crank shaft, there being carried by the crank shaft a connecting rod, the connecting rod having rigidly connected thereto a piston, the housing having acylinder insert which is of the self-lubricating type and the piston being mounted within the cylinder insert for reciprocatory movement.

A still further object of this invention is to provide an improved pump construction which includes a connecting rod having rigidly connected thereto a pump, the connecting rod being carried by a crank, the piston having a spherical segment edge portion whereby a perfect seal between the piston and a cylinder portion of the pump is maintained at all times.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure 1 is an elevational view of the compressor which is the subject of this invention and shows the general outline thereof;

Figure 2 is a top plan view of the compressor of Figure l with the gauges and various ttings thereof omitted for clarity purposes;

Figure 3 is an enlarged 'fragmentary vertical sectional view taken substantially upon the plane indicated by the section line 3 3 of Figure 2. and shows the details of the working parts of the compressor;

Figure 4 is an enlarged fragmentary vertical sectional viewtaken substantially upon the plane indicated by the section line 4-4 of Figure 3 and shows further the details of the working components of the compressor;

Figure 5 is an enlarged fragmentary transverse horizontal sectional view taken substantially upon the plane indicated by the section line 5 5 of Figure 3 and showsv the details of a valve assembly of the compressor;

Figure 6 is an enlarged fragmentary horizontal sectional view taken substantially upon the plane indicated by the section line 6-6 of Figure 3 and shows the details of the upper portion of the housing of the compressor, the upper portion including the cylinder part of the housing;

Figure 7 is an enlarged perspective view showing the details of the crank of the compressor;

Figure 8 is an enlarged exploded elevational view showing the details of a lter of the intake of the cornpressor; and

Figure 9 is an enlarged exploded vertical sectional view taken through one of the valves of t'he valve assembly.

Referring now to the drawings in detail, it will be seen that there is illustrated -in Figures l and 2 the air compressor assembly which is the subject of this invention, the assembly being referred to in general by the reference numeral 10. The air compressor assembly 10 includes an air compressor, which is referred to in general by the reference numeral 12, and an electric motor 14 which are mounted on a common base 16.

The air compressor 12 includes a housing which is referred to in general by the reference numeral 18. The housing 18 includes a pair of end walls 20 in which there are mounted a pair of aligned bearings 22. Suitably journaled in the bearings 22 is a crank 24 having a connecting rod journal 26.

The housing 18 also includes an upper cylinder portion 28 and a base 30. The base 30 is seated upon the base 16 and is secured thereto by suitable fasteners 32. The fasteners 32 are also secured to the base 16 downwardly depending resilient mounting pads 34.

The electric motor 14 also includes a mounting base` 36. The mounting base 36 is secured to the base 16 by suitable fasteners 38. The base 16 is also provided with resilient mounting pads 40 which are disposed beneath the electric motor 14 and are secured to the base 16 in any desired manner.

In order that the crank 24 may be driven by the electric motor 14, there is mounted on the armature shaft 42 of the electric motor 14 a drive pulley 44. The drive pulley 44 is aligned with a driven pulley 46 which is suitably secured on a projecting end of the crank 24. Entrained over the pulleys 46 and 44 and drivingly connecting the two together is a drive belt 48.

The compressor 12 also includes a valve assembly 50 which is mounted on the housing 18. Overlying and secured to the valve assembly 50 is a pressure reservoir dome 52.

The valve assembly 50 includes a cylindrical housing 54 having a lower mounting flange 56 and an upper mounting ange 58. The lower mounting ange 56 is disposed in abutment with a ange 60 at the upper end of the housing 18 and is secured thereto by a plurality of circumferentially spaced bolts 62. The housing 54 also includes a lower transverse wall 64 which forms a cylinder head for the cylinder portion 28 of the housing 18.

Clamped between the anges 56 and 60 is a peripheral edge portion of a diaphragm 66. The diaphragm 66 is sealed with respect to the housing 28 by means of a suitable sealing ring 68 which is recessed in the upper end of the housing 18.

Carried by the journal portion 26 of the crank 24 is a 3 connecting rod 70. The connecting rod 70 Yis provided with a bearing 72 and is locked on the journal portion 26 by means of a pair of locking rings 74. The bearing 72 is locked in the connecting rod 70 by a lockingl ring 76.

The upper -end of a connecting rod 70 includes an enlarged collar 78 and a threaded portion V80. yThreadedly engaged in the threaded portion 80 and seated on the collar 78 is a piston type diaphragm support '82. The diaphragm 66 has 'the central portion thereof clamped against the upper end of the diaphragm support 82 by means of a diaphragm vfollower 84 which is also threadedly engaged on the threaded portion 80. The support 82 and vthe diaphragm` follower 84 are provided with suitable spanner wrenchy openings 86 and 88, respectively, to facilitate their positioning and reinoval.v The diaphragm 66 is sealed with respect to the diaphragm support 82 by means of a suitable seal 90.

Inasmuch as the diaphragm support 82 is rigidly connected to the connecting rod 70, it is to be understood that it will pivot as well as reciprocate. In order that a seal may be provided between the walls of the cylinder portion 28 of the housing 18 and the diaphragm support 82 and also to provide a suitable guide for the diaphragm support 82, lthe diaphragm support 82 is provided with a spherical segment edge portion 92. Further, the cylinder portion 28 of the housing 18 is provided with a cylinder insert 94 which is formed of a soft lubricating material, such as an oil impregnated porous bronze material. Disposed between the cylinder insert 94 and the cylinder portion 28 is an oil impregnated felt wick 96. Oil is supplied to the 4felt wick 96 through an oil passage 98 normally closed by a plug 100, as is best illustrated in Figure 4.

'It is pointed out at this time that the seal between the diaphragm support 82 and the cylinder insert 94 may be such that such an arrangement is feasible wherein the diaphragm support 82 actually is the piston and the diaphragm would be omitted.

Referring now to Figure 4 in particular, it will be seen that the housing 54 of the valve assembly 50 has formed therein an intake chamber 102. The intake chamber 102 is communicated with the exterior of the housing 54 by an internally threaded bore 104. Formed in the partition wall 64 is an intake opening 106 in which there is seated an intake check valve 108. The partition wall 64 is also provided with an exhaust opening 110 in which there is seated an exhaust valve 112. The housing 54 is further provided with a drain opening 114 which is normally closed by `a plug 116.

The internally threaded bore 104 has engaged therein a short length of pipe 118 which carries an enlarged intake housing 120. As is best illustrated in Figure 8, the intake housing 120 is provided with an entrance opening 122 which has positioned therein a filter 124. The lfilter 124 is retained in place by a pair of screens 126 and 128 disposed on opposite sides thereof. The filter 124 and the screens 126 are disposed in an annular recess 128.

The intake valve 108 and exhaust valve 112 are identical. Accordingly, only the exhaust valve 112 will be described in detail. As is best illustrated in 'Fimlre 9, the exhaust valve 112 includes a housing v128 having a reduced portion 130 forming a shoulder 132 which permits the proper seating of the housing 128 Vin the exhaust opening 110. The housing 128 also includes an end wall 132 having an entrance opening 134 which also functions as a valve seat.

The housing 128 is cup shaped and seated therein is a small valve member 136 which is urged against the substance of the intake opening 134 to close the same by a spring 138. The spring 138 is retained in place by a suitable lock ring 140 which is seated in an annular groove 142 and an inner surface of the housing 128 remote from the end wall 132. v

The pressure dome 52 includes a mounting flange 144 which is disposed in abutment with the flange S8. The flanges 58 and 144 are secured together by a plurality of circumferentially spaced bolts 146.

As is best illustrated in Figures 1 and 2, the pressure dome 52 is provided with a plurality of outlet ttings 148, 150, 152 and 154. The fitting 148 is provided with a hose 156 which may be connected to any desired type of fitting which is intended to dispense compressed air. The outlet tting is provided with a safety valve 158. The outlet fitting 154 is provided with a suitable gauge 160. The outlet fitting 152 will be provided with a pressure regulator assembly (not shown) which may also be used to control the operation of the electric motor 14.

From the foregoing description of the air compressor 10, it will be readily apparent that the construction thereof is such that all parts thereof through which air passes will remain clean, there being no way in which oil and other vforeign matter from the operating parts of the air compressor may pass into the air passages thereof. Accordingly, the air .compressor 12 may be used in any hygienic work.

Although the unit has been described as an air cornpressor, it will be readily apparent that by connecting the pipe 118 to a fluid source, the unit will function as a conventional type of pump. Thus the air compressor 12 may be readily adapted to other uses than the mere compression of air. y

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and .changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and de scribed, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A pump construction comprising a housing having an upper portion providing an elongated cylinder wall, a crank rotatably mounted in said housing, a connecting rod connected to said crank, `a piston type diaphragm support connected to said connecting rod, a valve assembly closing the upper end of said, housing, a diaphragm clamped between said valve assembly and said housing, means securing said diaphragm to said diaphragm support, said diaphragm support being rigidly secured to said connecting rod and disposed within said cylinder portion for reciprocatory and rocking movement, said diaphragm support havinga spherical segment edge portion guidedly engaged with said cylinder wall.

2. A pump construction comprising a housing having an upper cylinder portion, a crank rotatably mounted in said housing, a connecting rod connected to said crank, a piston type diaphragm support connected to said connecting rod, a valve assembly closing the upper end of said housing, a diaphragm clamped between said valve assembly and said housing, means securing said diaphragm to said diaphragm support, said diaphragm support being rigidly secured to said connecting rod and disposed within said cylinder .portion for reciprocatory and rocking movement, said cylinder portion being in the form of an elongated cylinder insert formed of an oil impregnated porous material, said diaphragm support having a spherical segment edge portion guidedly en* gaged with said cylinder insert.

References Cited in the tile of this patent UNITED STATES PATENTS 1,383,549 Lang July 5, 1921 1,895,602 Brown Jan. 31, 1933 2,138,659 Kindig Nov. 29, 1938 2,471,796 Thiberg May 31, 1949 2,641,283 Houston June 9, 1953 

